X, nvidia, memory

[Greg O'Keefe]

Can anyone explain this (top display):

 12:36:43 up 51 min,  5 users,  load average: 0.06, 0.07, 0.02
 65 processes: 62 sleeping, 2 running, 1 zombie, 0 stopped
 CPU states:   3.0% user,   5.5% system,   0.0% nice,  91.5% idle
 Mem:    190780K total,   170652K used,    20128K free,     3244K buffers
 Swap:   128516K total,        0K used,   128516K free,   108928K cached

 PID USER     PRI  NI  SIZE SWAP  RSS SHARE STAT %CPU %MEM   TIME COMMAND
 392 root       9   0 18480    0  18M   920 S     0.0  9.6   0:30 dselect
 260 root      13 -10  174M 160M  14M  4708 S <   2.1  7.8   0:10 XFree86

In particular, how come it says X is using 160M of swap when I only have
128M, and none of it is used? I'd say its something to do with the
drivers for my new geforce II MX200. 

TIA

Greg O'Keefe